1. Field of the Invention
The present invention relates to an electively detachably coupled ball joint and pivot cup combination, and more particularly to a ball joint combination for electively detachably coupling a mast to a surfboard.
2. Description of the Prior Art
U.S. Pat. No. 3,487,800, entitled Wind-Propelled Apparatus, issued to Hoyle Schweitzer and James Drake on Jan. 6, 1970, teaches a wind-propelled apparatus which includes a mast which is universally mounted on a craft and which supports a boom and a sail. The position of the mast and sail is controllable by the user on the craft, but the mast is substantially free from pivotal restraint in the absence of such control. The wind-propelled apparatus may also include a pair of curved booms, which are arcuately athwart the mast. Wind-surfing has proved to be popular outdoor sport, but it is limited to lakes, large rivers or the ocean. Additionally, the mast is not detachably coupled to the surfboard. Furthermore, wind-surfing is also limited to individuals who are strong enough to lift the mast and sail out of the water.
U.S. Pat. No. 4,236,476, entitled Articulate Mast Footing Arrangement, in Particular for Wind Surfboards, issued to Alexander Solf and Christian Mrozek on Dec. 2, 1980, teaches a connecting arrangement for connecting two elements with one another, particularly a mast and a boat body of a wind surfboard. The connecting arrangement includes a male member which is connected with one of the elements, and a female member which is engageable with the male member with a snap action and is connected to another of the elements. At least one of the members connected with a respective one of the elements is rotatable within the horizontal plane. Preferably, this one member is rotatable within the range of 360 degrees. The male member and the female member together form a spherical joint. The male member may include a bolt section and a spherical section connected therewith whereas the female may include a bolt portion and a cup portion connected therewith for receiving the spherical section of the male member therein.
U.S. Pat. No. 3,982,766, entitled Wind-Propelled Skateboard, issued to James D. Budge on Sept. 28, 1976, teaches a wind-propelled skateboard which includes a body member having roller bearing wheels for transporting a skateboarder over a concrete or asphalt surface, a mast, which is detachably coupled to the body member in a manner that it is substantially free from pivotal restraint, a boom coupled to the mast by a hinge, and a sail coupled to the both the mast and the boom.
U.S. Pat. No. 4,130,292, entitled Apparatus for Propelling a Skate Board with Wind Currents, issued to A. Michael Lorenz on Dec. 19, 1978, teaches an apparatus for propelling a skate board with wind currents which includes a base plate coupled to the base of the skate board, a mast and sail combination, and a swivel member which is coupled to the base plate and which defines a mast receptacle for the mast. The swivel member provides free rotational movement of the mast without appreciable tilting movement of the mast in relation to the base plate. U.S. Pat. Nos. 4,200,302, 3,895,597 and 3,858,542 also teach sail-propelled vehicles.
U.S. Pat. No. 3,982,766 also teaches a combination of a pivot cup which is mounted to the base of the skateboard and a ball joint which is fixedly coupled to the mast so that the mast is detachably coupled to the skateboard.
In the July, 1981 issue of Sail there appeared an article, entitled "Board Sailing," in which the maststep was discussed on pages 16 and 18. The maststep is the most important part of the rigging of a wind-propelled surfboard. When one puts the mast up, he wants it to stay up. Pressure/friction, o-ring, and adjustable/expandable systems are three popular solutions to the problem. The mast is coupled by a universal joint to the surfboard. The pressure/friction system is the most straightforward for the coupling of the mast receptacle to the surfboard in that one just pushes hard the mast receptacle into the surfboard. The other two systems come out to easily in that the o-ring system tends to get sand in it and slips out of the surfboard and the adjustable/expandable system are difficult to tighten enough, especially when it is wet.
It would be desirable to provide a non-detachable mast receptacle and a mast which is electively detachably coupled to the mast receptacle. Presently there are no electively detaching universal joints. If there were such a universal joint when the sail and frame could be attached or detached in a few seconds without having to lay down the sail and frame while the attachment is made, and then pick up the sail and frame again to start riding. Furthermore it would allow the rider to lift the sail and mast out of the mast receptacle while riding in order for him to perform hand held sailing or place the mast in a different mast receptacle on the surfboard.